Gun perforator



A; J. ZSCHOKKE I GUN PERFORATOR Fil ed Dec. 8, 1941 Aug. 10, 1943.

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ATT NEY Patented Aug. 10, 1943 GUN PERFORATOR Arthur J. Zschokke, Huntington Park, CaliL, as-

signor to Lane-Wells Company, Los Angeles, Calif., a corporation of Delaware Application December a, 1941, Serial No. 422,088

8 Claims.

My invention relates to gun perforators; that is, devices adapted to be lowered within oil well casing for the purpose of perforating the casing by gunfire. Among the objects of my invention are:

First, to provide a gun perforator having a pluthe number of bullets that may be fired with a given number of conductors;

Third, to provide a gun perforator whichis particularly suitable for casing of small diameter, in that the gun bores may occupy a major portion of the diameter of the gun body to insure maximum muzzle velocity for a gun perforator of given diameter; and

Fourth, to provide a gun perforator wherein all of the electrical wiring is sealed within the gun body and need not be exposed at any point to well fluids.

With the above and other objects in view, as may appear hereinafter, reference is directed to the accompanying drawing, in which:

Figure 1 is a fragmentary elevational view of my gun perforator;

Figure 2 is a plan or end view of one of the .gun units, indicating by difierentiating dotted lines the arrangement of the several gun bores and associated elements of the gun units; and

Figure 3 is a fragmentary longitudinal sectional view through 3-3 of Figure 2, the view being taken through two annular planes.

My gun perforator comprises one or more gun bodies, designated generally by I, which incorporate multiple gun bore gun units 2. Each gun unit includes a primary cartridge chamber 3 extending axially into the gun body from an end thereof and offset from its axis. The cartridge chamber 3 is threaded at its outer end to receive a plug 4. The plug 4 is provided with a small bore which receives a. conductor 5 connected to a terminal 6 provided at the inner end of the plug 4. The inner end of the cartridge chamber 3 receives a cartridge 1 containing an explosive. The end of the cartridge adjacent the plug 4 is provided with an igniter 8 con- I taining a fuse wire adapted to be'electrically connected to the terminal 6. The inner portion, or cartridge-receiving portion, of the cartridge chamber 3 is intersected by a laterally extending gun bore 9 which receives a bullet indicated by dotted lines in Figure 2. The gun bore m g extend almost the-entire diameter of the gun, its inner end projecting past the intersection with the cartridge chamber 3 and receiving an auxiliary cartridge.

Below the gun bore 9 are arranged gun bores I0 and II, their axes preferably spaced apart so' that the gun bores are equally spaced around the periphery of the gun body. The three gun bores 9, III and l I, and associated parts, constitute the gun unit 2. The gun bores l0 and I lare intersected, respectively, by laterally extending secondary cartridge bores l2 and I3, the cartridge bores and their respective gun bores defining planes at right angles to the axis of the un body. The outer ends of the secondary cartridge bores l2 and I3 are closed by plugs I4, which are accessible from the exterior of the gun body. The inner ends ofthe secondary cartridge bores receive cartridges la similar to the cartridge 1, but without electrical ignition means.

Continuing axially from the primary cartridge chamber 3 is a main ignition passage l5 oflsmall diameter. This passage is intersected by two lateral ignition passages l6, which are drilled in planes parallel to the axes of'the gun bores I0 and H, and intersect the corresponding secdndary cartridge bores I2 and I3. v The outer ends of the lateral passages l6 are closed by suitable plugs ll.

The gun body I may contaln'one or two gun units. If two gun units are provided, the gun body is double-ended; that is, both ends receive plugs 4, are reduced in diameter and screwthreaded. Conductor passages l8 extend from end to end of the gun body and are adapted to receive conductors for electrical connection to the lower gun unit, or to succeeding gun units in adcoupling between the gun units to permit splicing or the lead wires 5a to the-conductor 5 passing through the plugs 4. If the several gun units are fired in sequence, then a single conductor is provided for each of the gun units. These conductors are suitably connected to a sequencing switch (not shown), which may be contained in a cable head 20 screw-threaded to the uppermost gun body. The cable head, in turn, is secured to a cable 2 I. If the gun units are fired simultaneously, a single lead wire 5a is required, from which the conductors 5 branch.

Operation of my gun perforator is as follows: Upon ignition of the primary cartridge I, by means of the conductor 5, not only is the bullet in gun bore 9 discharged, but the fiame from the cartridge 1 passes through the ignition passages I5 and IE to ignite the secondary cartridges la, so as to discharge the three projectiles practically simultaneously. By reason of the symmetrical arrangement of the gun bores around the gun body the forces are uniformly distributed so that there is little or no recoil to the gun. Furthermore, by reason of the equal distribution around the casing of the pressure, not only from the bu1-- lets themselves but the powder blast which follows, there is little or no distortion of the casing and the tendency to split is held to a minimum in spite of the fact that the holes are placed axially quite close together.

If it is desired to fire several units in sequence, individual lead wires connect to the several plugs 4. These leads are connected to a sequencing switch such as shown in the Johnston Patent No. 2,048,451. By means of the sequencing switch current is supplied to one gun unit at a time. 11 it is desired to fire all gun units simultaneously a single lead 5a is connected to all conductors I.

Because of the compact arrangement of the gun bores and their explosive cartridges, the ignition passages are extremely short, and the total volume oi. these passages, compared with the total volume of the three cartridge chambers, is extremely small so that little or no pressure loss occurs. By reason of the compact arrangement of the guns and the short length 01 the passages, and the symmetrical arrangement or the gun bores, the guns fire virtually simultaneously, so that at no time is there any appreciable pressure difierential between the several cartridge bores to create a condition wherein gases move at high velocity through the passage and cause appreciable erosion or enlargement of the ignition bores.

Various changesand alternate arrangements may be made within the scope of the appended claims, in which it is my intention to claim all novelty inherent in the invention.

,1 claim: g

1. A gun perforator comprising: a gun body having radially directed axially displaced gun bores, a cartridge chamber having an axially extending cartridge receiving portion intersecting at least one of said gun bores, other cartridge chambers, each having laterally disposed cargun bores, said cartridge-receiving portions defining with their respective gun bores planes which are normal to the axis of the gun body,

and ignition passages connecting said cartridge bores.

,2. A gun perforator comprising: a cylindrical gun body incorporating a pairor gun units, each un unit including a cartridge chamber lntersecting an axial end said body, laterally disposed cartridge chambers intersecting the sides of said gun body, ignition passages connecting said cartridge I chambers, and a gun bore for each of said'cartridge chambers; and coupling membeit'ls joining-a series of said gun bodies end to en 3. A gun perforator comprising:' a gun body having a cartridge chamber intersecting an axial end of said body, laterally disposed cartridge chambers intersecting the sides of said gun body, ignition passages connecting said cartridge chambers, and a gun bore for each of said cartridge means for igniting one 01' said cartridges, the remainder of said cartridges being responsive to flame from said electrically ignited cartridges delivered through said passages.

6. A gun perforator comprising: a body member defining a plurality of laterally directed glm bores, cartridge bores intersecting said gun bores,

and ignition passages interconnecting said bores:

tridge receiving portions for the other of said one of said cartridge bores extending axially and intersecting an end of said gun body, the re!- mainder extending laterally and intersecting the side of said gun body; removable plugs for said cartridge bores; and ignition means carried byone of said plugs.

'7. A gun perforator comprising: a gun body defining an axially directed cartridge bore, an ignition passage continuing axially therefrom, laterally directed cartridge bores, branch passages connecting said ignition passages therewith; and a laterally directed gun bore crossing each of said cartridge bores.

8. A gun periorator comprising: a gun body defining an axially directed cartridge bore, an ignition passagecontinuing axially thereirom,

laterally directed cartridge bores, branch passages connecting said ignition passages therewith; a laterally directed gun bore for each of said cartridge bores; an electrically fired cartridge for said axially directed cartridge bore; and plug means closing said axially directed cartridge bore and electrically connected with said cartridge.

ARTHUR J. ZSCHOKKE. 

